Haemochromatosis Flashcards
explain haemochromatosis
In hemochromatosis, which is a genetic disorder characterized by excessive iron absorption and accumulation in the body, the daily intake of iron may indeed increase due to the enhanced absorption. However, the ability to excrete excess iron is impaired in individuals with hemochromatosis.
In individuals with hemochromatosis, the body has difficulty regulating iron absorption and excretion. This leads to the net accumulation of iron over time. While the specific rate of iron excretion can vary among individuals with hemochromatosis, it is typically reduced compared to individuals without the disorder.
In individuals without hemochromatosis:
Iron intake is balanced by iron absorption and iron loss (primarily through mechanisms such as menstruation and the shedding of gastrointestinal epithelial cells).
Iron excretion roughly matches iron intake.
In individuals with hemochromatosis:
Iron absorption is increased, often leading to higher daily iron intake.
Iron excretion is impaired, meaning that the excess iron absorbed is not effectively excreted, resulting in iron accumulation in organs and tissues.
The impaired iron excretion is a key characteristic of hemochromatosis, and it contributes to the pathological effects of iron overload in the body.
The term “haemosiderosis” is often used to describe the pathological effects of iron overload in an organ, even when iron levels are elevated to sub-clinical levels, meaning that the individual may not yet exhibit significant symptoms. It is an early stage of iron overload and can progress to more severe conditions if not addressed. The distinction between haemochromatosis and haemosiderosis is based on the underlying causes, genetic factors, and the extent of iron accumulation in the body.
explain the signs of symptoms of haemochromatosis
Hemochromatosis is a genetic disorder characterized by excessive iron absorption and accumulation in various organs and tissues of the body. The symptoms and complications of hemochromatosis can vary among individuals, and some individuals may remain asymptomatic for an extended period. However, when symptoms do occur, they can be wide-ranging and include:
Chronic Liver Disease or Cirrhosis: Iron buildup in the liver can lead to liver damage, including fibrosis and cirrhosis. Symptoms of liver disease can include abdominal pain, jaundice (yellowing of the skin and eyes), and an enlarged liver.
Heart Problems: Hemochromatosis can lead to heart-related complications, including heart failure and arrhythmias (irregular heart rhythms). Symptoms may include shortness of breath, fatigue, and chest pain.
Diabetes: Iron deposition in the pancreas, particularly in the beta cells that produce insulin, can lead to diabetes mellitus. Symptoms of diabetes include increased thirst, frequent urination, and unexplained weight loss.
Fatigue: Excessive iron accumulation can cause general fatigue and weakness.
Hypogonadism and Low Libido: Hemochromatosis can affect the endocrine system, leading to hormonal imbalances. This can result in hypogonadism (reduced function of the gonads) and low libido.
Infertility: In men, iron overload can lead to testicular dysfunction and infertility. In women, it can affect fertility as well.
Amenorrhea: Iron accumulation in the ovaries can disrupt the menstrual cycle, leading to amenorrhea (absence of menstruation) in women.
Arthritis: Hemochromatosis can cause joint problems, including arthritis, often characterized by joint pain and swelling. Calcium pyrophosphate deposition in the joints can contribute to these symptoms, particularly in the index and middle fingers.
Bronzing of the Skin (Hemochromatosis Bronzing): This is a late sign of hemochromatosis and is characterized by a bronze or tan coloration of the skin. It typically occurs when iron overload is severe and can involve the face, hands, and other areas.
explain haemochromatosis bronzing
Hemochromatosis can indeed lead to skin discoloration, often referred to as “hemochromatosis bronzing.”
Hemochromatosis Bronzing:
This skin manifestation is characterized by a metallic grey or bronze-like discoloration of the skin.
It occurs due to the deposition of excess iron in the dermis, as well as the interaction between iron and melanin, the pigment responsible for skin, hair, and eye color.
The skin changes are typically generalized and diffuse, affecting various parts of the body.
Hemochromatosis bronzing is considered a late sign of the condition, and it often occurs when iron overload is severe.
explain the causes and classification of haemochromatosis
Primary Hemochromatosis:
Primary hemochromatosis refers to cases of the condition that are primarily caused by genetic mutations affecting iron metabolism. Several subtypes of primary hemochromatosis are recognized, each associated with specific genetic mutations:
Hereditary Hemochromatosis Type 1 (Classical): This is the most common form of hereditary hemochromatosis and is often associated with mutations in the HFE gene, particularly the C282Y mutation.
Hereditary Hemochromatosis Type 2 (Juvenile): This subtype can be caused by mutations in genes such as HJV (hemojuvelin) or HAMP (hepcidin antimicrobial peptide).
Hereditary Hemochromatosis Type 3: This subtype is associated with mutations in the transferrin receptor-2 (TFR2) gene.
Hereditary Hemochromatosis Type 4 (African): This form is linked to mutations in the ceruloplasmin (CP) gene and is more prevalent among individuals of African descent.
Other Hereditary Hemochromatosis Types: There are rare forms of hereditary hemochromatosis beyond the commonly recognized types, and these are typically associated with different genetic mutations.
Secondary Hemochromatosis:
Secondary hemochromatosis results from factors or conditions outside of genetic mutations and is often related to increased iron intake or iron overload due to various factors:
Chronic Hemolysis: Conditions that lead to the chronic breakdown of red blood cells, such as thalassemia or sickle cell disease, can cause secondary hemochromatosis.
Multiple Blood Transfusions: Repeated blood transfusions, often required in individuals with certain medical conditions, can lead to an excess of iron in the body.
Excess Iron Supplements: Overconsumption of iron supplements, often in the absence of an underlying medical need, can result in iron overload.
Excess Dietary Iron: A diet excessively high in iron-rich foods, especially when combined with other risk factors, can contribute to iron overload.
explain the treatment of haemochromatosis
Phlebotomy:
Phlebotomy is a primary treatment for hemochromatosis. It involves the removal of blood to reduce the body’s iron levels.
Initially, phlebotomy is performed once or twice a week, with approximately 500 mL of blood being removed each time. This helps to remove excess iron (approximately 200-250 mg) from the body.
The frequency of phlebotomy sessions may decrease once the serum ferritin level drops to less than 50 g/L, typically to around once every 3 months.
Dietary Recommendations:
People with hemochromatosis should avoid taking iron supplements or iron-containing medications to prevent further iron accumulation.
Vitamin C can enhance iron absorption, so it is advisable to limit the intake of foods or supplements high in vitamin C.
Alcohol consumption should also be restricted as it can contribute to liver damage in individuals with hemochromatosis.
Monitoring and managing conditions like cardiac failure, hepatic (liver) failure, or diabetes that can be associated with hemochromatosis are essential components of treatment.
Medication:
Deferoxamine is a medication used to remove excess iron from the body. It is administered parenterally (through injection or infusion).
Deferoxamine typically removes 10-20 mg of iron per day.
This medication is usually indicated in cases of severe anemia or severe hypoalbuminemia (low levels of albumin, a protein that binds to iron), where phlebotomy alone may not be sufficient. It is generally more costly and less effective compared to phlebotomy.
